The present invention relates to delivering material, such as quick-drying lining material, to a pipe.
Utilities pipes are commonly formed of metal and are susceptible to corrosion and other damage over time. Replacing damaged pipes can be difficult and expensive and it is known to provide them with a lining using a quick drying material, such as polyurethane.
GB2457596 describes methods and apparatus for lining pipes and locating an instrument within a pipe. Some versions of the apparatus disclosed comprise a nozzle for spraying lining materials inserted into a carrier air supply pipe, which is connected to the pipe that requires lining. These versions do not provide convenient access to the spray head, e.g. to perform material sampling operations, without having to fully disconnect the nozzle and the air supply pipe from the pipe being lined.
GB2457596 also discloses apparatus for locating an instrument, such as a spray head, within a pipe, the apparatus comprising a body portion with a cavity, a pipe engagement region for slideable engagement with a pipe, and an instrument retention portion for receiving at least a portion of an instrument/spray head. That apparatus is typically sealably engaged within a break in a buried domestic water pipe and allows a lining material spraying nozzle to be directed into the pipe whilst air is blown through the pipe in order to perform the lining process, and also allows the instrument retention portion to be slid outward for access, e.g. in order to perform a sampling operation. Typically, the apparatus is connected via a short pipe to air and lining material supplying components that are located within a nearby van. A problem associated with that apparatus is that it is not so practical for use with certain other types of pipes, such as gas riser pipes located within the walls of buildings, which are difficult to access and usually have significantly a smaller diameter (e.g. around 10 mm-76 mm). It is normally not convenient to cut such pipes in the described manner and insert instrument the locating apparatus in the middle of the break. Further, the apparatus does not allow air flow to continue uninterrupted whilst the instrument retention portion is in its sampling position. This can be problematic because the gel time of lining material can be brief (e.g. around 2-3 minutes) and stopping the warm air flow even temporarily can be detrimental in terms of the length of pipe that can be successfully lined by the process. Disconnecting the air flow in order to carry out a sampling operation also take time, leading to inefficiencies and increased costs, as well as resulting in unclean waste water.